Joist



Jan. 19, 1937.

E. D. cQDDlNGToN JoIsT Filed Sept. 3, 19555v my L Patented Jan. 19, 1937UNITED STATES PATENT OFFICE JOIST Application september 3, 1935, serianNo. 39,028

6 Claims.

The present invention has to do with a fabricated metal and concretejoist.

vThe objects of the invention include, among others, the provision ofthe following:

hereinafter appear, are obtained by the novel.

construction, unique arrangement, and improved combination of theseveral elements which constitute the invention, one embodiment of whichis illustrated inl the accompanying single sheet of drawing, hereby madea part of this specification, and in which:

Figure 1 is a side elevation of a joist embodying the subject matter ofthe present invention;

Figure 2 is a transverse section on the line 2-2 of Figure 1;

Figure 3 is a transverse section on the line 3-3 of Figure 2;

Figure 4 is a transverse section on the line 4-4 of Figure 1; and

Figure 5 is a sectional detail taken on the line 5-5 of Figure 1.

Like reference numerals are used to indicate similar parts in thedrawing and in the description of the invention which hereinafter isgiven.

The improved joist herein described and illustrated comprises a topchord I0, a bottom chord II, an end member I2, and an intermediate webmember I3.

The top and bottom chords I0 and I I are identical but reversed. Saidmembers comprise a U-shaped channel member I4 of suitable metallicmaterial having a narrow interior portion I5, a flaring side I6, and asecond flaring side I'I, the shape of which is reversed to that of theside I6. The sides I6 and' I1 define at their edges anges whichterminate parallel to the transverse interior portion I5.

Across the open side of the channel member I4 is a flat sheet ofmaterial I8 generally of the same width as the channel member from theedge of one flange to the edge of the opposite flange. This closuremember or flat strip of metal I8 is joined to the U-shaped member I4along its edge by a series of spot welds or in any other suitablemanner.

The two metal members comprising the parts I4 and I8 thus together denean elongated tube. 55 The opposite chord II of the joist is of an iden-A skeletonized metallic joist intokr which nails (Cl. 18S-37) ticalstructure and comprises a channel member having a flat base, sides withflanges and a metal strip; covering, the position of the parts beingreversed to those of the rst described chord I0. The first referred toU-shaped chord I0 and the second referred to U-shaped Achord II are eachfilled with cementitious material forming a core 20. This core may becomposed of a mixture of gypsum, Portland cement and sawdust,represented in the proportions, by weight, 55:20:9. This mixture ispacked into the casings in a dry state and moisture then introducedthrough openings I9 (Fig. 2.) Vformed in and throughout the length ofthe closure strip, to supply the necessary lWater of crystallization toharden the material. This process of fabrication is described andclaimed in my copending application Serial No. 39,022. Of course anyother suitable llers or processes of fabrication may be employed.

The U-shaped chords I0 and II arearranged in parallelism with their endsterminating in alinement. The chords I0 and II are of predeterminedstandard lengths. An end member I2 is disposed at each end of the joistand intermediate the end members I2 is a reenforcing and spacing web I3.The web comprises two elongated arcuate members oppositely disposed, thearcuate members being indicated 23 and 24 and being joined at theircenters and contacting surfaces by spot welding 22 (Fig. 5). Members 23and 24 after attachment one to another are folded at predeterminedintervals along their length.

At the folded sections, the members 23 and 24 are attened to provide asurface that will lie flat against the inner sides of chords I0 or II.In the structure illustrated in Figure 1, obliquely disposed sections ofweb I3 are indicated by the numerals 25. The flattened out portions ofthe web I3 lying against the chord II are designated 26 and theflattened portions lying against the chord I0 are indicated 2l. Thelength of the members 23 and 24 is determined by the length of thechords III and Il, and by the length of the end members I2 now to bedescribed in detail.

The end members I2 overlie a flattened extension 28 of the Web I3. Eachend member I2 comprises an exposed side or end 30, a side 3l contactingthe inner surface of chord I0, a side 32 at the interior of the joist,and a side 33 contacting the web extension 28. The sides 30, 3|, 32, and33 form a rectangle and will be ordinarily made of a single strip ofmaterial.

Two dish shaped members 36 and 38 having, respectively, peripheralflanges 31 and 39 are telescoped into the opposite sides of therectangular frame of the end member I2. Spot Welding 40 may be used tomaintain the member 36 in position. It is customary to ll member I2 witha cementitious material which will receive nails driven thereinto, suchconcrete fill being indicated by the numeral 42. Member 38 is secured inposition by spot Welding 4I after the ll 42 has been inserted.

The joist generally is assembled by inserting between the chords I0 andII the web I3, and thereafter inserting the end members I2. All of theparts are secured in position by spot welding'. Plate 36 is then ttedinto position if not previously inserted and welded. As previouslystated, end member I2 at its bottom side overlies a at end section 28 ofthe web I3. Member I2 is attached to chord I0 and web extension 28 byAspot Welding 43 and 44, and web I3 is secured to chords I0 and II bywelds 45 and 46.

The iill for the end members I2 may be inserted Vafter said members arespot welded to the chords II! and II, and chords ID and II may be filledafter all spot Welding has been completed except the welding of sidepiece 38 tov member I2, which is attached after the lls are inserted.

The structure described is exceedingly strong. The web comprisingopposed arcuate strips joined along their longitudinal lines andflattened out at spaced intervals for attachment to chords I0 and IIresists both compressing and torsional 'strains to a remarkable degreewhen the weight of the structure is considered. The chords and endmembers readily receive nails and may be used as, and in place of woodenjoists. The joist 'is simple to fabricate and the cost of assembly andmaterials is relatively low.

I claim:

1. A metal and nailable concrete joist comprising spaced apartcomposition filled chords, and a web therebetween comprising pairedopposed arcuate members.

vengaging the chords at spaced intervals, the sections of said stripscontacting said chords being iiat and the intermediate sections of saidweb comprising opposed arcuate channels joined one to another alongtheir longitudinal median lines.

5. ,A metal and concrete jost comprising channel shaped chords iill'edwith a nailable composition, and a web therebetween, said web comprisingpaired longitudinal strips joined one to another lat their longitudinalmedian lines, said strips having ilat portions contacting the innerfaces of said chords, and being substantially X-shaped in cross-sectionbetween said contacting portions.

6. A joist comprising opposed U-shaped metal chords ofchannel shapecovered with a Vmetal strip at their edges and iilled with a nailablecomposition, parallelopiped end members of metal and a nailablecomposition between said chords,

and a web between said chords extending unbrokenly from one end membertothe other end member, said Web comprising a pair of elongated stripsarcuate in cross section and joined one to another at their longitudinalmedian line, said strips being folded alternately in one direction andthen the other and being joined at succeeding folds to opposite chords.

EDWDT D. CODDINGTON.

